JP2009037815A - Battery sealing method, battery sealing jig, and battery manufacturing method - Google Patents

Abstract

A battery sealing method with improved adhesion of a sealing material is provided.
A battery sealing method provided by the present invention covers a sealing material 12 over an opening 11 of a battery case 10 and presses the sealing material 12 with a jig 20 so as to adhere to the periphery of the opening 11 of the battery case 10. It has the process of making it. The jig 20 includes an elastic pressing portion 21 that presses the sealing material 12 while being elastically deformed. According to this battery sealing method, since the battery sealing jig 20 has the elastic pressing portion 21 at the tip, the elastic pressing is performed when the sealing material 12 covered on the opening 11 of the battery case 10 is pressed. The part 21 is deformed according to the opening 11 of the battery case 10. The sealing material 12 is well pressed around the opening 11 by the elastic pressing portion 21 and is in close contact therewith.
[Selection] Figure 3

Description

  The present invention relates to a battery sealing method in which a sealing material is attached to an opening of a battery case to seal the opening, a battery sealing jig used in the battery sealing method, and a battery manufacturing method.

In a battery, for example, a lithium ion secondary battery, an electrode body unit (referred to as an electrode structure including at least one positive electrode and a negative electrode; hereinafter the same) is accommodated in a battery case (exterior container), and an electrolyte is injected into the injection hole. Then, the injection hole is sealed (intermediate sealing). And after supplying an electric current from the exterior and performing initial charge, the gas is extracted and the discharge hole which discharges | emits gas is sealed (for example, Unexamined-Japanese-Patent No. 2002-324588). Thereby, after the initial charging, gas is generated by a chemical reaction, but the battery case can be prevented from expanding due to the gas.
JP 2002-324586 A

The above-described intermediate sealing is performed after removing moisture in the battery case, housing the electrode body unit in the battery case, and injecting the electrolyte from an opening (injection hole) formed in the battery case. In the intermediate sealing, a sealing material made of an adhesive tape is pasted so as to cover the opening of the battery case, and the opening is sealed.
For example, as shown in FIG. 1, the sealing material 12 is carefully covered over the opening 11 of the battery case 10, and no air 14 remains between the sealing material 12 and the surface 13 of the battery case 10 as shown in FIG. 2. As described above, the sealing material 12 is carefully traced with the finger 15 to bring the sealing material 12 into close contact with the periphery of the opening 11 of the battery case 10.
In this case, when the gas is extracted after the initial charging, the sealing material attached to the opening (injection hole) with the intermediate sealing may be peeled off, and the gas may be discharged from the opening (injection hole). There is no need to form. Then, after the gas is removed, the opening (injection hole) is sealed by means such as welding with a metal seal member, for example.

However, when the sealing material is applied to the opening of the battery case, if the sealing material is wrinkled or if air enters between the sealing material and the battery case, the sealing performance of the intermediate seal is deteriorated. In particular, when initial charging is performed after intermediate sealing, gas is generated in the battery case, the atmospheric pressure in the battery case increases, and pressure is applied to the sealing material from the inside of the battery case. For this reason, if the sealing material is not applied well to the battery case, a part of the sealing material may be peeled off due to the increase in the atmospheric pressure, and leakage may occur in the intermediate sealing. In the intermediate sealing, it is necessary to prevent leakage even when the air pressure in the battery case increases due to initial charging.
If the airtightness of the intermediate seal is poor, foreign matters such as moisture may enter the battery case, and the battery performance may be reduced. In order to detect such a defect in the intermediate sealing, it is necessary to inspect whether or not gas has leaked after the intermediate sealing in the battery manufacturing process.
In order to improve the airtightness of the intermediate seal, it is necessary to carefully apply a sealing material. However, depending on the level of skill of the worker, there may be a large difference in work speed and error occurrence frequency. Therefore, in order to improve production efficiency, it is desirable to improve the workability of such intermediate sealing and reduce errors in intermediate sealing. This is one of the objects of the present invention.

A battery sealing method according to the present invention is a battery sealing method in which a sealing material is attached to an opening of a battery case to seal the opening, the sealing material is placed on the opening of the battery case, and the sealing material is attached to a jig. And a step of closely adhering around the opening of the battery case. In this battery sealing method, a jig having an elastic pressing portion that presses the sealing material while being elastically deformed is used.
In this case, since the sealing material covering the opening of the battery case is pressed by the elastic pressing portion of the jig, the sealing material is uniformly distributed over the entire circumference of the periphery of the opening according to the elastic deformation of the elastic pressing portion at the tip of the jig. In close contact. By improving the adhesion of the sealing material, the opening can be sealed more reliably. Moreover, according to this method, the difference in the skill level of the worker and the difference in work speed can be reduced, and the sealing performance can be ensured more reliably. The elastic pressing portion can be formed of, for example, a foam material or rubber.

  Moreover, in a certain embodiment, the front-end | tip of an elastic press part may be formed in the convex curve. In this case, when the sealing material is pressed by the tip of the elastic pressing portion, the sealing material can be brought into close contact from the center side (periphery of the opening) to the outside according to the elastic deformation of the elastic pressing portion at the tip of the jig. When the sealing material is put on the opening of the battery case, even if bubbles exist between the peripheral edge of the opening and the sealing material, the bubbles remain between the peripheral edge of the opening and the sealing material. Can be prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the member or site | part which has the same effect | action. In addition, the following embodiment only illustrates one embodiment of the present invention, and the present invention is not limited to the following embodiment.

As shown in FIG. 3, the battery sealing method includes a step of covering the opening 11 of the battery case 10 with the sealing material 12 covered with the opening 11 of the battery case 10 and pressing the sealing material 12 with the jig 20. Have. The jig 20 includes an elastic pressing portion 21 that presses the sealing material 12 while being elastically deformed.
According to this battery sealing method, since the battery sealing jig 20 has the elastic pressing portion 21 at the tip, the elastic pressing is performed when the sealing material 12 covered on the opening 11 of the battery case 10 is pressed. The part 21 is deformed according to the opening 11 of the battery case 10. The sealing material 12 is well pressed around the opening 11 by the elastic pressing portion 21 and is in close contact therewith.

  In this embodiment, as shown in FIG. 3, the battery case 10 has an opening (here, an electrolyte injection hole) 11 for injection of an electrolyte and degassing. This battery sealing method can be suitably implemented for the method of sealing the electrolyte injection hole 11, but can also be applied to sealing of openings for other uses and purposes. In this battery sealing method, first, a sealing material 12 is put on the opening (electrolyte injection hole) 11 of the battery case 10. In this embodiment, the sealing material 12 is an adhesive tape in which an adhesive material is coated on one side of the film. The sealing material 12 has a shape that can cover the electrolyte injection hole 11 formed in the battery case 10. For example, the sealing material 12 may be carefully covered with the electrolyte solution injection hole 11 of the battery case 10 using tweezers. The sealing material 12 used here is not particularly limited as long as it is made of a material that achieves desired airtightness and mechanical strength. For example, it is made of polyimide, polyester, or polyethylene. The sealing material is preferable.

Further, the battery sealing jig 20 has an elastic pressing portion 21 at the tip. In this embodiment, the battery sealing jig 20 has a pressing shaft portion 22 and an elastic pressing portion 21 attached to the tip of the pressing shaft portion 22 as shown in FIG. The pressing shaft portion 22 has a required rigidity and is a portion that presses the elastic pressing portion 21. In this embodiment, the elastic pressing portion 21 is made of a foam material (sponge).
Specifically, in this embodiment, the elastic pressing portion 21 is formed of silicon foam rubber, is not too soft, and has the required elastic deformation performance and elastic reaction force. In this embodiment, the elastic pressing portion 21 is further formed with a convex curved surface 21a at the tip.
The end surface of the pressing shaft portion 22 to which the elastic pressing portion 21 is attached has a shape that can deform the elastic pressing portion 21 into an appropriate shape when the elastic pressing portion 21 is pressed against the battery case 10. Good. In this embodiment, the pressing shaft portion 22 has an end surface 22a larger than the opening (electrolyte injection hole) 11 of the battery case 10, and the elastic pressing portion 21 is attached to the end surface 22a. In this embodiment, the elastic pressing portion 21 is bonded to the end surface 22a of the pressing shaft portion 22 using an adhesive.

  As shown in FIG. 4, the elastic pressing portion 21 corresponds to the shape around the opening (electrolyte injection hole) 11 of the battery case 10 when the opening (electrolyte injection hole) 11 of the battery case 10 is pressed. And deform. At this time, the elastic pressing portion 21 may be deformed so as to be larger than the opening (electrolyte injection hole) 11 of the battery case 10. As a result, the sealing material 12 can be brought into close contact with the opening (electrolyte injection hole) 11 of the battery case 10. In this embodiment, the elastic pressing portion 21 is deformed more largely than the sealing material 12.

  As shown in FIG. 3, the battery sealing method covers the battery case 10 by covering the opening (electrolyte injection hole) 11 of the battery case 10 with the sealing material 12 and pressing the sealing material 12 with the battery sealing jig 20. Are closely attached around the opening (electrolyte injection hole) 11. In this embodiment, the battery sealing jig 20 has an elastic pressing portion 21 at the tip. As shown in FIG. 4, the elastic pressing portion 21 is formed in the opening (electrolyte injection hole) 11 of the battery case 10 when the sealing material 12 placed on the opening (electrolyte injection hole) 11 of the battery case 10 is pressed. Deforms accordingly. In this embodiment, the elastic pressing portion 21 is deformed more greatly than the sealing material 12 as shown in FIG. For this reason, the entire surface of the sealing material 12 can be pressed around the opening (electrolyte injection hole) 11 of the battery case 10, and as shown in FIG. ) Can be neatly pasted around 11. According to this method, the difference in the skill level of the operator and the difference in work speed can be reduced, and the sealing performance of the seal can be ensured.

  Moreover, in this embodiment, the front-end | tip of the elastic press part 21 is the convex curve 21a. In this embodiment, as shown in FIG. 6, when the elastic pressing portion 21 presses against the opening (electrolyte injection hole) 11 of the battery case 10, the top of the convex curved surface 21 a of the elastic pressing portion 21 is replaced with the battery case 10. The elastic pressing portion 21 is pressed against the opening 11 of the battery case 10 (strictly, the sealing material 12 covering the electrolyte injection hole 11 of the battery case 10) toward the opening (electrolyte injection hole) 11. . When the elastic pressing portion 21 is pressed against the opening (electrolyte injection hole) 11 of the battery case 10 as described above, the elastic pressing portion 21 hits the periphery of the opening (electrolyte injection hole) 11 as shown in FIG. As shown in FIG. 4, the contact is made around the opening (electrolyte injection hole) 11. For this reason, the sealing material 12 gradually comes into close contact with the periphery of the opening (electrolyte injection hole) 11. Thereby, the air between the sealing material 12 and the surface of the battery case 10 can be pushed out well, and the air can be prevented from remaining between the sealing material 12 and the surface of the battery case 10. Thus, when the front-end | tip of the elastic press part 21 is the convex curve 21a, the sealing material 12 can be affixed more cleanly by the surface 13 of the battery case 10, and battery sealing can be performed more reliably. Moreover, according to this method, the difference in the skill level of the worker and the difference in the work speed can be further reduced, and the sealing performance can be ensured more reliably.

  As mentioned above, although one embodiment of the battery sealing method and the battery sealing jig according to the present invention has been described, the battery sealing method and the battery sealing jig according to the present invention are not limited to the above-described embodiments. .

  For example, the elastic pressing portion of the battery sealing jig is exemplified by a silicon foam rubber. As described above, the elastic pressing portion is deformed according to the surface shape of the battery case when the sealing material is pressed against the battery case, and the sealing material is attached to the surface of the battery case. It only has to be demonstrated. For this reason, the material of the elastic pressing portion is not limited to the above-described silicon foam rubber. Further, the elastic pressing portion may be made of a non-foamed material, for example, rubber.

  Further, in the above-described embodiment, the tip of the elastic pressing portion is formed in a convex curved surface, but when the tip of the elastic pressing portion is pressed around the opening of the battery case, the tip of the elastic pressing portion is around the opening of the battery case. What is necessary is just to deform | transform according to a shape, and the front-end | tip does not necessarily need to be formed in the convex curve.

  For example, the elastic pressing portion 21 may be a cylindrical member having a larger plane than the opening 11 of the battery case 10 as shown in FIG. Even when the elastic pressing portion 21 is a convex curved surface, the convex curved surface does not need to be formed with a uniform radius of curvature, and may be a free curved surface. For example, as shown in FIG. 8, the tip of the elastic pressing portion 21 may have a convex curved surface 21a as a whole and a flat surface 21b at the central portion. As described above, if the tip of the elastic pressing portion 21 is the convex curved surface 21 a, the sealing material 12 can easily be brought into close contact with the periphery of the opening 11 gradually, and the sealing material 12 is attached to the surface of the battery case 10. It is easy to adhere more neatly. Moreover, as shown in FIG. 9, the elastic pressing part 21 may be spherical. Further, the structure of the pressing shaft portion 22 and the structure of attaching the elastic pressing portion 21 to the pressing shaft portion 22 are not limited to the above-described embodiment, and various modifications can be made.

This battery sealing method can be applied, for example, as an intermediate sealing step before initial charging of a secondary battery that seals the electrolyte injection hole. Examples of such secondary batteries include lithium ion secondary batteries. This battery sealing method is simple and stable in hermeticity by using the above-described battery sealing jig. In addition, when removing the gas after the initial charging, it is only necessary to remove the sealing material attached to the injection hole with the intermediate sealing and to discharge the gas from the injection hole, and there is no need to separately form a discharge hole, etc. It is also advantageous in terms of workability and work cost. Therefore, it is suitable as one process of the manufacturing method of a battery which has an intermediate sealing process like a lithium ion secondary battery.
Therefore, the present invention, as another aspect, is disclosed herein in a battery manufacturing method including an intermediate sealing step of sealing an electrolyte injection hole provided in a part of a battery case before initial charging. Provided is a method for manufacturing a battery (typically a secondary battery such as a lithium ion secondary battery), wherein any one of the battery sealing methods is performed as an intermediate sealing process.

The battery manufacturing method provided in the present invention is a method characterized by carrying out the battery sealing method of the present invention as an intermediate sealing step, and other steps (for example, a predetermined prepared in a case). The step of housing the electrode body unit and the electrolyte, the step of sealing the battery case after housing them, and the step of initial charging) may be exactly the same as the conventional battery manufacturing process, and are not particularly limited.
For example, taking an in-vehicle lithium ion secondary battery as an example, an electrode body unit accommodated in a battery case is generally used to constitute a unit cell equipped in a typical in-vehicle assembled battery, for example. It may be the same as that of the electrode body unit and is not particularly limited. For example, a long positive electrode current collector (aluminum foil) in which an appropriate positive electrode active material layer is formed in advance, and a long negative electrode current collector (copper in which an appropriate negative electrode active material layer is formed in advance) A wound electrode body unit is housed in which a foil is wound together with a long separator (for example, a sheet made of a porous polyolefin resin). Since the present invention is not characterized by the configuration of the electrode body unit (the material of the positive and negative electrode current collector or separator, the composition of the active material layer, etc.), detailed description of the electrode body unit is omitted.

Moreover, as an electrolyte accommodated in a case with an electrode body unit, it may be the same as that used with the conventional lithium ion secondary battery, The content in particular is not restrict | limited. For example, a suitable nonaqueous electrolytic solution (for example, a nonaqueous electrolytic solution such as a mixed solvent of diethyl carbonate and ethylene carbonate containing an appropriate amount of a lithium salt such as LiPF ₆ ) can be preferably used. Since the present invention is not characterized by the configuration of the electrolyte, a detailed description of the electrolyte is omitted.

  Further, according to the present invention, the tightness of the sealing material is improved, so that the airtightness is increased, and moisture (water vapor in the air) enters the battery case in the intermediate sealing process (that is, during the initial charging). Can be more reliably prevented. For this reason, for example, the water content in the non-aqueous electrolyte of a lithium ion secondary battery is prevented from increasing during the initial charge, and as a result, the battery performance is prevented from being lowered and the high performance battery (lithium ion secondary battery is Batteries, etc.) can be provided.

The battery sealing method according to the present invention can be widely applied as a method for an operator to seal the opening of a battery case. Moreover, the difference in sealing depending on the skill level of the operator can be reduced by implementing the battery sealing method according to the present invention. And the NG (failure) rate in an intermediate | middle sealing process can be reduced and the work speed of the whole battery manufacturing process can be raised as a result.
In addition, the battery sealing jig according to the present invention is attached to a machine, and the adhesiveness is high even when the sealing material is attached to a predetermined opening (for example, an electrolyte injection hole) of the battery case by mechanical operation of the machine. It is possible to apply the sealing material efficiently while maintaining the above. As described above, by using the battery sealing jig, it is possible to efficiently perform the sealing process (for example, the intermediate sealing step).

The figure which shows an intermediate | middle sealing process. The figure which shows an intermediate | middle sealing process. The figure which shows the battery sealing method which concerns on one Embodiment of this invention. The figure which shows the battery sealing method which concerns on one Embodiment of this invention. The figure which shows the state which closely_contact | adhered the sealing material around the opening of the battery case by the battery sealing method which concerns on one Embodiment of this invention. The figure which shows the battery sealing method which concerns on one Embodiment of this invention. The figure which shows the jig | tool for battery sealing which concerns on other embodiment of this invention. The figure which shows the jig | tool for battery sealing which concerns on other embodiment of this invention. The figure which shows the jig | tool for battery sealing which concerns on other embodiment of this invention.

Explanation of symbols

10 Battery case 11 Opening (electrolyte injection hole)
12 sealing material 13 surface 20 battery sealing jig 21 elastic pressing portion 22 pressing shaft portion

Claims (9)

A battery sealing method for sealing the opening by sticking a sealing material to the opening of the battery case,
Covering the opening of the battery case with the sealing material, and pressing the sealing material with a jig to closely contact the opening of the battery case;
The battery sealing method, wherein the jig has an elastic pressing portion that presses the sealing material while being elastically deformed.   The battery sealing method according to claim 1, wherein the elastic pressing portion is formed of a foam material.   The battery sealing method according to claim 1, wherein the elastic pressing portion is formed of rubber.   The battery sealing method according to claim 1, wherein a tip of the elastic pressing portion is a convex curved surface. In the battery manufacturing method, having an intermediate sealing step of sealing the electrolyte injection hole provided in a part of the battery case before initial charging,
A battery manufacturing method, wherein the battery sealing method according to claim 1 is performed as the intermediate sealing step.   A battery sealing jig that has an elastic pressing portion at a tip, presses a sealing material placed over an opening of a battery case, and closely contacts the sealing material around the opening.   The battery sealing jig according to claim 6, wherein the elastic pressing portion is formed of a foam material.   The battery sealing jig according to claim 6, wherein the elastic pressing portion is formed of rubber.   The battery sealing jig according to claim 6, wherein a tip of the elastic pressing portion is a convex curved surface.

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